Then, with a certain significance, he repeated his operations with the salt on his own plate. The symbol 4 was too plain to be missed. I looked at him searchingly. In no way that I could see did he resemble the young Templeton, or James the footman, or any other of the various personalities we had come across. Nevertheless, I was convinced that I had to do with no less than the redoubtable Number Four himself. In his voice there was certainly a faint resemblance to the buttoned-up stranger who had called upon us in Paris.

I looked round, undecided as to my course of action. Reading my thoughts, he smiled and gently shook his head.

“I should not advise it,” he remarked. “Remember what came of your hasty action in Paris. Let me assure you that my way of retreat is well assured. Your ideas are inclined to be a little crude, Captain Hastings, if I may say so.”

“You devil,” I said, choking with rage, “you incarnate devil!”